Accessing GPDs from experiment --- potential of a high-luminosity EIC ---

Abstract

We discuss modeling of generalized parton distributions (GPDs), their access from present experiments, and the phenomenological potential of an electron-ion collider. In particular, we present a comparison of phenomenological models of GPD H, extracted from hard exclusive meson and photon production. Specific emphasis is given to the utilization of evolution effects at moderate x Bj in a future high-luminosity experiment within a larger Q 2 lever arm.

Parton distributions and lattice-QCD calculations: Toward 3D structure

“…(Kriesten et al, 2020), conformal moments based models (Müller et al, 2014) used in the analysis of Refs. (Kumericki et al, 2011;Kumerički and Müller, 2016), as well as parametrizations based on double distributions (Goloskokov and Kroll, 2008).…”

A set of generalized parton distributions

“…Note that the GPDs extracted in [2] are not optimized for the latter kinematical region. It should also be mentioned that in the same spirit a DVCS analysis is performed in [9,12].…”

The GPD H̃ and spin correlations in wide-angle Compton scattering

“…The handbag approach can be generalized to deeply virtual meson electroproduction (DVMP) and to wide-angle photoproduction of mesons. It turned out that in both cases the numerical estimations of cross sections fail by order of magnitude in comparison with experiment at least for Jefferson Lab kinematics [6,7,8]. For pion electroproduction an explanation of this failure has been found: lacking contributions from transversity GPDs, formally of twist-3 nature, which are strongly enhanced by the chiral condensate [9,10,11].…”